Ulnar nerve compression at the elbow caused by a prominent medial head of the triceps and an anconeus epitrochlearis muscle.

A number of musculo-tendinous variations around the medial epicondyle have been alleged to cause ulnar nerve compression. Subluxation of the ulnar nerve, a "snapping" separate medial head of triceps, a prominent medial head of triceps covering the ulnar nerve, anconeus epitrochlearis, Osborne's band, and the ligament of Struthers have been implicated. We present a case of clearcut compression of the ulnar nerve at two levels just at and posterior to the epicondyle by a tightly applied prominent head of the triceps, and at a more distal level beneath an anconeus epitrochlearis muscle.